(ITS#7586) MDB tests crash

[josephg@gmail.com]

Full_Name: Joseph Gentle
Version: Gitorius master 2d6aed7
OS: MacOS
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (50.1.123.217)


Using the latest version of lmdb in https://gitorious.org/mdb/mdb (2d6aed7), I
went into the liblmdb directory, ran make then ran the tests.

All tests crash with Segmentation Fault. Problem can be reproduced compiling
with gcc or clang, and gcc on linux.

env->me_txns is NULL in mdb.c line 1840.


Process 63426 stopped
* thread #1: tid = 0x1c03, 0x0000000100001a2d
mtest`mdb_txn_renew0(txn=0x0000000100103de0) + 125 at mdb.c:1840, stop reason =
EXC_BAD_ACCESS (code=1, address=0x28)
    frame #0: 0x0000000100001a2d mtest`mdb_txn_renew0(txn=0x0000000100103de0) +
125 at mdb.c:1840
   1837		} else {
   1838			LOCK_MUTEX_W(env);
   1839	
-> 1840			txn->mt_txnid = env->me_txns->mti_txnid;
   1841			txn->mt_toggle = txn->mt_txnid & 1;
   1842			txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
   1843			txn->mt_txnid++;
(lldb) p env
(MDB_env *) $0 = 0x0000000100103c70
(lldb) p env->me_txns
(MDB_txninfo *) $1 = 0x0000000000000000